Interpretive Summary: Process evaluation can tell you if an intervention was delivered as intended. The HEALTHY Study was a school-based prevention trial implemented in 21 middle schools across the US with the goal of preventing Type 2 diabetes in middle school students. Process evaluation of the Physical Education (PE) intervention indicated that this part of the study was generally implemented as intended and that students were physically active approximately 33 minutes during PE class. The teachers were engaged in implementing the program. The most common barrier observed for the PE program was student misbehavior. Our findings suggests that the PE intervention was implemented and received as intended despite some barriers.

Technical Abstract:
Process evaluation is an assessment of the implementation of an intervention. A process evaluation component was embedded in the HEALTHY study, a primary prevention trial for Type 2 diabetes implemented over 3 years in 21 middle schools across the United States. The HEALTHY physical education (PE) intervention aimed at maximizing student engagement in moderate-to-vigorous physical activity through delivery of structured lesson plans by PE teachers. Process evaluation data collected via class observations and interventionist interviews assessed fidelity, dose delivered, implementor participation, dose received, and barriers. Process evaluation results indicate a high level of fidelity in implementing HEALTHY PE activities and offering 225 min of PE every 10 school days. Concerning dose delivered, students were active for approximately 33 min of class, representing an average of 61% of the class time. Results also indicate that PE teachers were generally engaged in implementing the HEALTHY PE curriculum. Data on dose received showed that students were highly engaged with the PE intervention; however, student misbehavior was the most common barrier observed during classes. Other barriers included teacher disengagement, large classes, limited gym space, and poor classroom management. Findings suggest that the PE intervention was generally implemented and received as intended despite several barriers.